1. Field of the Invention
The present invention is drawn to subscriber telephone apparatus and more particularly to a caller identification device which displays the identity of calling parties.
2. Background Art
A search of the background art directed to the subject matter of the present invention conducted in the U.S. Patent and Trademark Office disclosed the following U.S. Pat. Nos. 4,672,660 4,805,207 4,817,133 4,894,861 4,926,471.
Many telephone companies throughout the world have now started offering so-called calling number display features (CND) as part of an optional feature service to regular telephone subscribers. In the United States, many of the major operating companies are offering this new service where the telephone subscriber may exercise an appropriate option is able to receive information to identify the calling party on a device which includes a display which can be attached to the telephone line. This service is available from local telephone companies at an additional monthly charge and requires an add-on hardware device at the customer's premise. Obviously, this feature allows the user to screen incoming calls and answer only when desired. At the present time, hardware to implement calling device in the form of a so-called black box device, or add-on, which would be connected to a normal telephone line provides this service. In the usual arrangement, the telephone system offering such service, sends from the telephone central office a set of signals during the ring cycle which are decoded at the customer premises and are displayed on the calling number display.
As indicated in the prior art calling number devices, the circuitry evaluates the ring cycle and decodes appropriate signals received through internal control logics in the calling number identification unit and then typically displays the information on a liquid crystal device. This unit, typically speaking, is attached to the tip and ring of the telephone line in parallel with the telephone instrument. It is the oh,jeer of the present invention to provide such service along with additional services, such as for the provision of conversion to audio signals, to computer ports for direct computer interface, and to normal television for display while watching programs. The unit may have true universality for an office as well as home use.